Record Information
Version1.0
StatusDetected and Quantified
Creation Date2020-12-10 18:36:56 UTC
Update Date2022-08-31 06:06:49 UTC
Metabolite IDMMDBc0000401
Metabolite Identification
Common NameMethionine sulfoxide
DescriptionMethionine sulfoxide (MetO) or L-Methionine sulfoxide belongs to the class of organic compounds known as L-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. Methionine sulfoxide arises through the oxidation of methionine residues in proteins by reactive oxygen species (ROS). Oxidation of methionine results in a mixture of the two diastereomers methionine-S-sulfoxide and methionine-R-sulfoxide. Methionine oxidation is considered an important post-translational event in protein synthesis and can affect the function and activity of many proteins. The oxidation of methionine plays an important role in vivo, during biological conditions of oxidative stress, as well as for protein stability in vitro. For instance, the oxidation of methionine residues in tissue proteins can cause them to misfold or otherwise render them dysfunctional. Most organisms have developed systems to restore these oxidized methionine residues back to methionine (i.e., converting MetO to Met). This reduction is done by the methionine sulfoxide reductase (MSR) system, with the MSRs type A (MSRA) and type B (MSRB) being specific for the S and R forms of MetO, respectively (PMID: 28917052 ). In mammals, the selenoprotein MSRB1 plays an important MetO repair function, and its expression is tightly regulated by dietary selenium (PMID: 28917052 ). The eventual proteolyis of any unfolded or misfolded MetO modified proteins leads to the production of free methionine sulfoxide that can be detected in blood or urine.  MetO is not a proteogenic amino acid and cannot be incorporated into proteins during ribosomal mediated translation. Levels of free MetO are closely correlated with levels of oxidative stress. Methionine sulfoxide (MetO), increases with age in body tissues, and its presence is believed by some to contribute to biological aging.  Levels of MetO are also increased in individuals suffering from chronic bacterial infections (tuberculosis) or other conditions causing inflammation (PMID: 32123207 ). Similarly, MetO is increased in the serum/plasma of patients diagnosed with sepsis (PMID: 27501420 ). This likely reflects the high production of ROS species arising from the overactive (but underperforming) immune response.
Structure
Synonyms
ValueSource
L-Methionine sulfoxideChEBI
Methionine S-oxideChEBI
L-Methionine sulphoxideGenerator
Methionine sulphoxideGenerator
Methionine sulfoxide, (R-(r*,s*))-isomerHMDB
Methionine sulfoxide, 35S-labeled, (+-)-isomerHMDB
Methionine sulfoxide, (S-(r*,s*))-isomerHMDB
Methionine sulfoxide, (2S)-isomerHMDB
Methionine sulfoxide, (2R)-isomerHMDB
Methionine sulfoxide, (+-)-isomerHMDB
DL-Methionine sulfoxideHMDB
L-Methionine S-oxideHMDB
Methionine sulfoxideHMDB
Molecular FormulaC5H11NO3S
Average Mass165.21
Monoisotopic Mass165.045964392
IUPAC Name(2S)-2-amino-4-methanesulfinylbutanoic acid
Traditional NameL-methionine sulfoxide
CAS Registry NumberNot Available
SMILES
CS(=O)CC[C@H](N)C(O)=O
InChI Identifier
InChI=1S/C5H11NO3S/c1-10(9)3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8)/t4-,10?/m0/s1
InChI KeyQEFRNWWLZKMPFJ-YGVKFDHGSA-N